The Installer writes log files to the ORACLE_INVENTORY_LOCATION/logs directory on UNIX systems and to the ORACLE_INVENTORY_LOCATION\logs directory on Windows systems.
On UNIX systems, if you do not know the location of your Oracle Inventory directory, you can find it in the ORACLE_HOME/oraInst.loc file.
On Microsoft Windows systems, the default location for the inventory directory is C:\Program Files\Oracle\Inventory\logs.
The server log files are created in the <DOMAIN_HOME>/server/<servername/logs directory.
The following install log files are written to the log directory:
installDATE-TIME_STAMP.log
installDATE-TIME_STAMP.out
installActionsDATE-TIME_STAMP.log
installProfileDATE-TIME_STAMP.log
oraInstallDATE-TIME_STAMP.err
oraInstallDATE-TIME_STAMP.log